Refrigeration system for vehicles



m., M3, 1953 JB JOHNSON REFRIGERATION SYSTEM FOR VEHICLES Filed NOV. 17.1949 IIA/VENTUR. J@ JUHNSON FIG. 3

ATTORNEY Patented Oct. 13, 1953 REFRIGERATION SYSTEM FOR VEHICLES JBJohnson, Tyler, Tex., assignor of twenty-four per cent to Wilford C.Thompson and twentyfour per cent to Pickens Morris, both of Tyler,

Tex.

Application November 17, 1949, Serial No. 127,920

2 Claims.

This invention relates to refrigeration systems and more particularly tosuch a system specifically adapted for incorporation in a motor vehicleto cool the passenger compartment.

Heretofore, numerous refrigeration systems for use in motor vehicleshave been developed and marketed but many of these were relatively largecomplicated and cumbersome aifairs located in the luggage compartment ofthe vehicle and occupied a large amount of such space. This rendered itdiiiicult to accommodate a suiicient quantity of baggage on a long tripand likewise these prior systems included complicated piping andflexible tubing arrangements which, due to the ever present vibration inthe motor vehicle, were a continuous source of annoyance andmaintenanceV troubles. Further, these prior systems were relativelyexpensive both to install and maintain and the power requirements weresuch thatithe normal battery and electrical system ci the automobile wassubjected to a severe overload.

It is, accordingly, an object of this invention to provide arefrigeration system particularly adapted for installation in a motorvehicle, which system occupies a minimum of space, utilizes a power takeoli already provided on the motor, and may conveniently utilize theconventional heater already installed in the vehicle as a cooling unit.

It is a further object of this invention to provide a refrigerationsystem for use. in a motor vehicley which system incorporates a noveldiaphragm` type. compressor, which compressor includes safety featuresto prevent damage thereto in the event the compressor becomes iilledwith relatively incompressible liquid during periods of non-use.

Itis a further object of this invention to provide a refrigerationsystem for incorporation in a motor vehicle, which system utilizes adiaphragrn type compressor and in which there is provided a novelcontrol means for rendering the compressorv inoperative or for varyingthe output capacity thereofv between Zero and maximum.

It is a further object oi this invention to provide a refrigerationsystem particularly adapted for' use in a motor vehicle which. is ofextremely simple and economical construction and. which may be installedin the vehicle by relatively unskilled labor resulting in a cooling unitwhich is readily available to a large majority of motor vehicle owners.

Further objects and advantages of the invention will be apparent fromthe following specication taken in conjunction with the accom'- panyingdrawings, wherein:

Fig. 1 is a fragmentary diagrammatic view showing the forward portion ofa motor vehicle 'with the refrigeration system of this inventioninstalled therein;

Fig. 2, a fragmentary longitudinal sectional View showing the internalstructure of the diaphragm type compressor and the manner of supportingand driving the same from the engine of the motor vehicle;

Fig. 3, a top plan view of the compressor shown in Fig. 2 with the coverplate removed;

Fig. 4, a fragmentary View with parts in section for greater clarityshowing a portion of the compressor drive mechanism and associatedcontrol means; and,

Fig. 5, a sectional View showing the details of one of the valvesincorporated in the diaphragm of the compressor.

With continued reference to the drawings there is shown diagrammaticallyin Fig. 1, the forward portion of a motor vehicle comprising a hood l,radiator H, cooling fan l2, motor i3, steering wheel i4, and instrumentpanel i5. 'Ihe motor i3 includes the usual cylinder block l uponwhich ismounted the conventional fuel pump il secured to a casting it providedwith a flange I9 secured to the moto-r block i6 by screw threadedfastening means or the like 20.

The refrigeration system of this invention includes a diaphragm typecompressor 2| havin-g a discharge or high pressure line 22 leading to acondenser 23 positioned in such a manner as to receive a continuous iiowof air' from the cooling fan l2. If desired, for ease of installationorl increased efficiency the condenser 23 may be positioned between theradiator il and grill Il. From the condenser 23 a conduit M' leads to aliquid refrigerant receiver 25 from which a liquid line 25 communicateswith an evaporator 2l which may conveniently take the form of theconventional hot Water heater normally installed on the lire wall inmotor vehicles. If desired, however, a specially designed evaporator maybe utilized instead of the hot water heater and in some instances wouldresult in increased eiliciency. From the evaporator 21 a suction line 28leads to the suction side of the compressor 2 i. Also disposed intheliquid line 26 is an expansion valve 29 the operation of which iscontrolled by a conventional heat responsive bulb 30 in contact with theliquid line adjacent the evaporator 21 and connected by a tube 3l withthe valve 29.

In order to insure a rapid circulation of air over the evaporator 21there may be provided a motor driven fan 32 which blows airtherethrough, this fan receiving air from the interior of the vehicleand projecting the same through the coil of the evaporator 21 to producea cooling thereof and a consequent reduction of temperature within thepassenger compartment of the vehicle. If desired, the speed of the fan32 may be controlled by the `usual switch, not shown, mounted on theinstrument panel for this purpose,

The diaphragm type compressor 2| utilized in this refrigeration systemis of novel construction and includes a main compressor body 33 whichmay be conveniently constructed in the form of a relatively thickcircular plate, although this body may be of any form desired. Body 33is provided in its upper face with a recess having an angularly disposedperipheral wall 34, the central portion of the body 33 beingcounter-bored at 35 and 36 for a purpose to be presently described. Acover plate 31 is provided with a frusto-conical recess 38 in its lowerface which together with the recess in the body 33 constitutes thecompressor chamber. Cover plate 31 is adapted to be positioned on thebody 33 and be secured thereto by screw threaded fastening means or thelike 39. A diaphragm 40 of suitable flexible material is clamped betweenbody 33 and cover plate 31 adjacent the periphery thereof, thisdiaphragm extending completely across the compressor chamber and beingclamped to a reciprocating valve plate 4| by a clamping plate 42provided with a plurality of apertures 43 and a central portion 44having a recess 45 therein for a purpose to be presently described.Clamping plate 42 is fastened to the valve plate 4| by a plurality ofscrew threaded fastening means or the like 46.

Valve plate 4| is provided with a plurality of apertures 41 terminatingin counterbores 48 adjacent the upper surface of the plate. Positionedin each of the counterbores is a valve 49 shown in detail in Fig. 5.

Valve 49 comprises a stamped sheet metal body 56 of steppedconstruction, there being a plurality of slots or apertures 5| thereinto permit the passage of fluid through the valve. Valve body 50 is soformed as to provide a centrally located aperture 52, the side wall ofwhich terminates inwardly of the body 50 to provide a valve seat 53.Positioned upon this seat is a valve member 54 in the form of a discwhich is normally held in engagement with the seat 53 by a compressionspring 55 engaging the valve member 54 and the body 50. A portion of thebody 50 provides an annular flange 56 which may be conveniently utilizedto secure the valve 49 in position in the valve plate 4|. This operationis accomplished by setting the valve 49 in the counterbore 48, therebeing a plurality of screw threaded fasteners or the like 51 positionedaround the counterbore with a portion of each head of the fasteners 51engaging the ange 56 and the upper surface of the plate 4| to securelyclamp the valve 49 in position within the counterbore 48.

Valve plate 4| is provided on its lower surface with a centrally locatedcircular boss 58 having generally hemispherical recesses 59 therein, theouter surface of the boss 58 being provided with a taper threadedportion 60 adapted to receive a taper threaded nut 6|. This structureprovides a convenient means for attaching the diaphragm 40, valve plate4|, and clamping plate 42 to the drive mechanism to be presentlydescribed.

In order to conveniently mount or support the compressor body 33 andassociated parts and also to house the driving mechanism there may beprovided a tubular member 62 having a ange 63 at one end secured tocompressor body 33 by screw threaded fastening means or the like 64. Theopposite end of tubular member 62 terminates in a flange 65 which may beconveniently secured by screw threaded fastening means 66 to nange 61provided on casting I8.

The novel drive mechanism incorporated in this compressor comprises acup shaped cylindrical member 68 slidably received within the tubularmember 62, cylindrical member 68 also slidably receiving a second cupshaped cylindrical member 63 to provide a telescoping assembly.Positioned within the members 618 and 69 and in engagement with theirend walls is a compression spring 10 which serves to transmitcompressive force from member 69 to member 68.

Member 68 is provided with an axially extending rod like portion 1|terminating in a ball 12 received in the hemispherical recesses 59 inboss 58. Ball 12 is loosely clamped in position by taper threaded nut 6|to provide a ball and socket joint.

Cylindrical member 69 terminates at its lower end in an axiallyextending rod like portion or element 13 which is slidably received inan aperture 14 in closure plate 15 which may be secured in place in acounterbore 16 in the flange 65 by screw threaded fastening means 11.Aperture 14, together with the cylindrical inner wall of the tubularmember 62 provides a guide means for the drive assembly. However, closemanufacturing tolerances need not be maintained for these parts sinceall that is necessary is a relatively loose sliding t.

In order to prevent leakage between the compressor chamber and theinterior of tubular member 62, a sealing diaphragm 'I8 may be clamped incounterbore 3G in compressor body 33 by a clamping plate 19 secured byscrew threaded fastening means or the like 80. Sealing diaphragm `A`18is provided with a centrally located aperture received over the boss 58and is clamped in position thereon by taper threaded nut 6|. Thisstructure provides an eiective seal between the compressor chamber andthe interior of tubular member 62 and prevents any leakage of fluidtherebetween.

In order to vent any fluid pressure which may build up within thetelescoping cup shaped members 68 and 69 and also to permit theintroduction of lubricant thereto, member 68 may be provided with a ventopening 8| and member 69 with a vent openingr 82. Likewise closure plate15 may be provided with vent openings 83 whereby lubricant may beintroduced into the assembly and fluid pressure vented therefrom.

The above described compressor may be conveniently driven by theconventional drive mechanism utilized to operate the fuel pump |1. Thismechanism comprises a cam 84 mounted on the cam shaft 85 of the engine|3 and a rocker arm 86 extending through an aperture 81 in the engineblock I6, the rocker arm 86 being pivotally mounted at 88 on the castingI8. The inner end of rocker arm 86 is provided with a cam follower 89 inengagement with the surface of the cam 84 and the opposite end of rockerarm 86 is provided with an elongated slot 90 through which passes a pin9| serving to connect rod 13 and rod 92 which is connected to the fuelpump |1. As will be seen from an inspection of Fig. 2, upon rotamaythreadedly receive an inlet valve 9,4.

94. is provided with a valve. member 05 which is..

tion of the cam. shaft 85 the cam 84 will cause the rocker arm 8.5i tooscillate. about pivot thus reciprocating pin 9| and rods 13 and 9.2attached thereto which resultsy in actuation" of the fuel pump |1. andthe above described compressorV in, a manner to be, presentlydescribed..

The suction chamber of the. compressor of this; invention is provided bythe. recess in the. body 33 and in order to permit the flow of fluidthereto there is provided a screw threaded bore 9,3; which Val-venormally urged to closedposition by a compres:- sion. spring 9.6..However,` upon. upward movev ment of; the diaphragm Ml to: create a.vacuum within the suction chamber; the pressure of fluid on the outersurface. of valve memberV 95. willi move the same inwardly against theaction. of spring 96 thus permitting the: iiow of fluid to the. suctionchamber.

The. recess 38 inthe cover plate- 3,1 provides. a compression chamberand in order to cond-uct compressed flu-id therefromy there is providedin the cover plate 31 aV screw threaded bore 91 in which is; threadedlyreceived an outlet valve 38.. Valve 9.8. is provided with a valvemember9i).V which is normally held in closed position by a compression spring|00, this4 valve preventing iiow of fluid fromr the` exterior of thecompressor intoy the compression chamber but operating c against theaction of spring to permit the flow of compressed iiuid, therefrom.

In order to.v insure return. ofv the diaphragm 40 and associated partsto lowermost` position thereis. provided a return spring I0.|. with oneendpositioned recess. 45. in clamping plate l2 and with the. oppositeend positioned in a recess |112.I inV cover plate 31.

In operation. the reciprocatory movement of rod 1,3 will be. transmittedin one direction to..

spring; |0.|V the valve membersv 54 in valves 4,0 o

will open. against. the action of springs 55 to allow fluidV in thesuction chamber to now upwardly through slots into the compressionchamber thus recharging the same with fluid to permit reciprocation of'thecompression cycle.

Obviously the compression spring may be so calibratedV that the.pressure developed in the compressor chamber will. be governed therebysince if suc-h pressure exceeds the compression strength of spring 10this springV will yield and the diaphragm and associated parts will`remain stationary until cup shaped member 69 returns to its lowermostposition at which time return spring 10| will return the diaphragm toits lowermost position. This structure determines the maximum pressuredeveloped by the compressor and also affords a safety device in theevent the compression chamber becomes filled or partially lled withliquid or other comparatively incompressible fluid whereby a positivemovement of the diaphragm would result in damage to the parts withpossible rupture of the diaphragm or breakage of associated elements.

Since it is often desirable to discontinue op- Civ eration of thecompressorfwithout stopping. the,v

engine and also since it is sometimes:v desirable' to varythe.-eapacityof the compressor, a simple, eici'ent and novel controlmechanismis'provided which is shown in, detail in Fig.. 4.

This control mechanism comprises a bell' crank:V

lever |02 whichmay bek conveniently pivoted at. |03 on ears. |04extending from the wall of the:

tubular member 62', a portion of the bell crankv lever |02 extendingthrough an aperture |05; in. the. wall of`V the tubular member. Theinner end of the. bell crank; lever |02' is provided with;

a yoke |00,A the arms thereof being disposed onv each sideor theextensionv 1|, the yoke armsV terminating in enlarged portions |01providing;l bearing surfaces to engage the lower surface oftaperthreaded nut 6|. The opposite end of bell crank lever |02 is: providedwith an apertured portion; |08: adapted to receive an operating. or

control wire |09 which is clamped in position byv a screw threadedfastening means or the like H301. The control wire |00 may extendthrough a flex:- ible sheath ||I to a` point convenient tothe operator,the wire |09 being provided with a fingerv engaging knob l2 which may beutilized for:

v venting reciprocation of the same under the ac` tion of rod 13 andcompression spring 10; This will. result in reducing the compressorcapacity to zero and the compressor will remain, in inoperativecondition until wire |309v is. actuated to. movebell crank lever |02 incounterclockwise direction whereupon` diaphragm 40 and associ.- atedparts wil-l be reciprocated through a path of? ltravel depending uponthe position of enlarged portion |01. If the movement of the bell cranklever |02 is suihcient to move the enlarged; portion |01 entirely outofv contact` with nut 6| then the diaphragm 40. and. associated partswill: move through their full path of travel andthe compressor willdeliver its maximum capacity whereas if the enlarged portion |015occupiessome intermediate position this will. serve to block downwardmovement of; the nut 6:|; and diaphragm. 40 whereby the path of, travelwill be some intermediate value between maximum and zero. This structureresults in providing an inn-itevariatiOn in; the capacity of thecompressor between zero and maximum and frictional means, not shown isprovided inv the control system to retain the bell crank lever m2' andenlarged portionv i0? in the desired position.,

Obviously, various modications of this. control. mechanism may be:employed such as. a cam in engagement with; the nut 6|, the cam having.a proper contour to accomplish the desired variation in diaphragmmovement. The basic principle, however, would be the same regardless ofwhat specific mechanism was employed and the structure disclosed in Fig.Il is by way of illustration only.

The refrigeration system shown in Fig. l operates in a conventionalmanner, the compressor 2| serving to compress :the refrigerant anddischarge the same through line 22 to condenser 23 wherein the gaseousrefrigerant is condensed to a liquid, the liquid flowing through line 24to liquid receiver 25. liquid refrigerant flows from receiver 25 throughline 26 and expansion valve 29 into the evaporator 27 where the liquidrefrigerant is converted to a gas and in this process absorbs heat fromthe air passing around the coils of the evaporator 2'! under the actionof fan 32. The gasied refrigerant in the evaporator is then drawn oithrough suction line 28 to the suction chamber of the compressor 2l.

The operation of the refrigeration system may be controlled through themedium of bell crank lever |02, control wire IGS, and finger engagingknob I I2, this control acting to stop the com- .presser reciprocationwhether the engine I3 is running or not, this control also beingoperable to vary the capacity of the compressor for any desired outputbetween zero and maximum.

The drive mechanism includes the compression spring 'I9 and associatedparts and is particularly valuable in this application since duringperiods of non use liquid refrigerant tends to collect within thecompressor chamber and consequently if the diaphragm were actuated by apositive drive there would be extreme likelihood of severe damage :tothe parts if not actual breakage of the compressor casting. The springl0 allows the driving mechanism to yield without damage to the partsuntil such time as the liquid within the com pressor chamber has drainedtherefrom at which time Athe compressor will commence normal operation.

The driving mechanism also provides a very eicient safety device in thatthe compression spring may be calibrated for the maximum pressuredesired and consequently under abnormal conditions there would be nodanger of the pressure within the refrigeration system reaching adangerous value since the maximum pressure obtainable would be thatdetermined by the cempression strength of the spring 79. Such a safetydevice is particularly desirable in an installation of #this sort wherethe speed of the engine I3 varies over a wide range and if operated fora considerable period of time at a relatively high rate of speedabnormal pressures might build up in the refrigeration system. Thissituation could of course be controlled by proper actuation of the knobH2 but rather than depend on the skill of the operator the spring 'I0serves to f eliminate any danger from this source, if the operator doesforget to properly adjust knob I I2.

It will be seen that by `the above described invention there has beenprovided a relatively simple yet highly efficient refrigeration systemparticularly adapted for installation in a motor vehicle where space isat a premium and in which adequate control and safety devices have beenincorporated, the compressor utilized in the system being of aparticularly inexpensive yet highly efficient type and being adapted tobe easily installed in the motor vehicle by relatively unskilled laborthereby resulting in a relatively in- As required, the

expensive device and one which requires rela` tively little maintenanceor upkeep.`

It will be obvious to those skilled in the art that various changes maybe made in the invention without departing from the spirit and scopethereof and therefore the invention is not limited by that which isshown in the drawings and described in the specification but only asindicated in fthe appended claims.

What is claimed is:

1. A refrigeration system for motor vehicles including a compressor, acondenser, a liquid refrigerant receiver, an expansion valve, and anevaporator connected by conduits, said compressor comprising a body anda cover member recessed to provide a compressor chamber, a diaphragmwithin -said chamber, a support for said compressor comprising a tubularmember secured to the body, means for reciprocating said diaphragmcomprising a first cup-shaped member slidably disposed in said tubularmember, a second cup-shaped member telescopically received within saidfirst cup-shaped member, a calibrated compression spring disposed withinsaid cup-shaped members, means connecting said first cup-shaped memberand said diaphragm, means for connecting said second cupshaped member topower means whereby said diaphragm may be reciprocated by said springthe pressure developed in ysaid chamber and in said refrigeration systembeing dependent upon the compression strength of said spring.

2. A refrigeration system for motor vehicles including a compressor, acondenser, a liquid refrigerant receiver, an expansion valve, and anevaporator connected by conduits, said compressor including a diaphragmand yieldable means for reciprocating the same and a control means forsaid compressor comprising a pivotally mounted bell crank lever one endthereof terminating in a yoke, enlarged bearing portions upon said yokeconstructed and arranged to engage said diaphragm, a control Wiresecured to the opposite end of said bell crank lever whereby uponoperation of said control wire to pivot said bell crank lever saidbearing portions will en*- gage said diaphragm to permit limitedmovement thereof, said control means being effective to control thecapacity of said compressor between zero and maximum whereby therefrigerating effect of said system may be controlled.

JB JOHNSON.

References Cited in the le of this patent UNITED STATES PATENTS NumberName Date 2,078,804 McConkey Apr. 27, 1937 2,162,512 McPherson et al.June 13, 1939 2,199,090 Palmer Apr. 30, 1940 2,256,237 Broden Sept. 16,1941 2,256,987 Meyerhoer Sept. 23, 1941 2,276,568 Erickson Mar'. 17,1942

